Tuesday, April 24, 2018

Beelzebufo: Beast of the Week

This week let's check out a prehistoric amphibian!  Enter Beelzebufo ampinga!

Beelzebufo was a large frog that  lived in what is now Northern Madagascar, during the Late Cretaceous, about 70 million years ago.  Specimens are fragmentary, but the largest individuals appear to have been between nine and ten inches long from snout to rump.  Like all amphibians, Beelzebufo would have been a meat-eater as an adult. (Assuming it started as a tadpole, which commonly will eat algae.) The genus name translates to "Beelzebub Toad", in reference to Beelzebub, the biblical demon and sometimes alternate name for Satan.  The species name, ampinga, means "shield" in Malagasy, in reference to the frog's wide, broad skull.

Beelzebufo emerging from hibernation during the first heavy rain of the year.  Watercolor reconstruction by Christopher DiPiazza.

When Beelzebufo was first published, very fragmentary remains were on the fossil record at the time. This mostly consisted of material from the skull, which was proportionally huge for any frog.  That being said, early size estimates put Beelzebufo at sixteen inches long, making it by far the largest member of anura (Order that includes frogs and toads.  Toads are actually within the frog group.  So all toads are frogs but not all frogs are toads...so we can just say frogs.) of all time.  More recently, however, more fossils from this giant frog have been uncovered, including limbs that were paired with skull fragments that are similar in size to the largest skull fragments already known.  As it turns out, Beelzebufo wasn't quite as huge as originally thought, being closer to nine or ten inches long instead of sixteen.  It just had a gigantic head for its body.  Nine or ten inches is still really big for a frog, though.

Diagram of Beelzebufo's skeleton from Evans' 2014 paper.  Dark blue is previously known material.  Light blue is newer material that led them to believe this frog was smaller than sixteen inches.  Grey is guesswork, using modern frog relatives as reference.

Another cool thing about Beelzebufo, was that it had a rough texture on the surface of its skull.  This suggests there was some kind of tough covering there in life, possibly as defense against predators or maybe even for protection during combat within the species.  Large species of frogs today get extremely violent towards each other, especially during mating time, so assuming Beelzebufo could have engaged in similar activity during the Cretaceous isn't out of the question.

It was determined, by measuring the bite force of modern frogs, then scaling the numbers up, that the largest Beelzebufos would have had extremely powerful bites for frogs at over 2,000 Newtons of force, or 400 pounds per square inch.  Beelzebufo's teeth were numerous, and closely packed in the mouth, forming a sort of ridge-like structure lining the jaws.  This combination of features would have ensured that whatever Beelzebufo decided to strike at, most likely did not escape once bitten.  Like modern frogs, Beelzebufo probably had a sticky tongue it could flip out to initially capture prey, pulling it towards the jaws, which would do the rest of the work before swallowing the prey whole.  Also like modern frogs, it is safe to assume Beelzebufo was a voracious hunter, not particularly caring what kind of prey it went after, as long as it could fit in its gigantic mouth.  In my time as a zookeeper, I have witnessed living frogs even attempt to eat prey that was larger than them. (and by prey I mean my hand.)

Close up diagram from Evans 2014 paper showing the tough skull surface and the teeth of Beelzebufo.

The environment Beelzebufo would have called home appears to have been seasonally dry, which was quenched by annual wet seasons.  Amphibians normally cannot survive in dry habitats.  We can observe many amphibians today get around this environmental hurdle by hibernating part of the year, then waking up to breed during the rainy season.  It is possible that Beelzebufo could have done something similar.  In addition to dryness, this frog would have needed to watch out for meat-eating dinosaurs, like Masiakasaurus, or even the large Majungasaurus, that might have viewed the large frog as prey.

That is all for this week!  As always comment below!


Evans, S., Groenke, J., Jones, M., Turner, A., Krause, D. 2014. New material of Beelzebufo, a hyperossified frog (Amphibia: Anura) from the Late Cretaceous of MadagascarPLoS One. 9, 1: e87236.

Evans, S., Jones, M., Krause, D. 2008. A giant frog with South American affinities from thee Late Cretaceous of MadagascarPNAS. 105, 8: 2951-2956

 Lappin, A. Kristopher; Wilcox, S.C.; Moriarty, D. J.; Stoeppler, Stephanie A. R.; Evans, Susan E.,; Jones, Marc E. H. (2017). "Bite force in the horned frog (Ceratophrys cranwelli) with implications for extinct giant frogs". Scientific Reports

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